在 Java 中将 Jersey 集成到 Undertow 服务器

Question

I have written a Java application with the objective of hosting it using the Undertow server and embedding Jersey so as to implement various API Requests. The Application.java class is responsible for hosting the Server and ProductEndpoint.java has the implementation using Jersey.

I have implemented 5 classes. I am using Eclipse IDE.

Here is my code snippet:-

1. Application.java

package mainClass;

import static io.undertow.servlet.Servlets.listener;
import static io.undertow.servlet.Servlets.servlet;

import javax.servlet.ServletException;

import org.glassfish.jersey.servlet.ServletContainer;
import org.jboss.weld.environment.servlet.Listener;

import io.undertow.Handlers;
import io.undertow.Undertow;
import io.undertow.server.handlers.PathHandler;
import io.undertow.servlet.Servlets;
import io.undertow.servlet.api.DeploymentInfo;
import io.undertow.servlet.api.DeploymentManager;


public class Application {
    private static Undertow server;

    public static void main(String[] args) throws ServletException {
        startContainer(9090);
    }

    public static void stopContainer(){
        server.stop();
    }

    public static void startContainer(int port) throws ServletException {
        DeploymentInfo servletBuilder = Servlets.deployment();

        servletBuilder
                .setClassLoader(Application.class.getClassLoader())
                .setContextPath("/mainClass")
                .setDeploymentName("mainClass.war")
                .addListeners(listener(Listener.class))
                .addServlets(servlet("jerseyServlet", ServletContainer.class)
                        .setLoadOnStartup(1)
                        .addInitParam("javax.ws.rs.Application", JerseyApp.class.getName())
                        .addMapping("/api/*"));

        DeploymentManager manager = Servlets.defaultContainer().addDeployment(servletBuilder);
        manager.deploy();
        PathHandler path = Handlers.path(Handlers.redirect("/mainClass"))
                .addPrefixPath("/mainClass", manager.start());

        server =
                Undertow
                        .builder()
                        .addHttpListener(port, "localhost")
                        .setHandler(path)
                        .build();

        server.start();
    }
}

2. JerseyApp.java

package mainClass;

import javax.ws.rs.ApplicationPath;

import org.glassfish.jersey.server.ResourceConfig;

@ApplicationPath("/api/*")
public class JerseyApp extends ResourceConfig {
    public JerseyApp() {
        packages(true, "mainClass");
    }
}

3. ObjectMapperFactory .java

package mainClass;

import com.fasterxml.jackson.annotation.JsonInclude;
import com.fasterxml.jackson.databind.DeserializationFeature;
import com.fasterxml.jackson.databind.ObjectMapper;


public class ObjectMapperFactory {
    private static final ObjectMapper OBJECT_MAPPER;

    static {
        OBJECT_MAPPER = new ObjectMapper();

        OBJECT_MAPPER.configure(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES, false);
        OBJECT_MAPPER.setSerializationInclusion(JsonInclude.Include.NON_NULL);
    }

    private ObjectMapperFactory() {
    }

    public static ObjectMapper get() {
        return OBJECT_MAPPER;
    }
}

4. ObjectMapperResolver.java

package mainClass;

import javax.ws.rs.ext.ContextResolver;
import javax.ws.rs.ext.Provider;

import com.fasterxml.jackson.databind.ObjectMapper;

@Provider
public class ObjectMapperResolver implements ContextResolver<ObjectMapper> {
    @Override
    public ObjectMapper getContext(Class<?> type) {
        return ObjectMapperFactory.get();
    }
}

5. ProductEndpoint.java

package mainClass;


import javax.enterprise.context.ApplicationScoped;
import javax.ws.rs.GET;
import javax.ws.rs.Path;


@Path("/v1")
@ApplicationScoped
public class ProductEndpoint {


    @GET
    @Path("/hello")
    public String PrintHello(){

        return "Hello";
    }


    @GET
    @Path("/hai")
    public String PrintHai(){

        return "Hai";
    }

    @GET
    @Path("/selfhost")
    public String PrintSelfHost(){

        return "Self Host";
    }

}

However, On running the Java code, an error is as shown below is thrown and I am unable to host the Server.

Feb 10, 2020 5:22:17 PM org.jboss.weld.environment.servlet.Listener contextInitialized
INFO: WELD-ENV-001007: Initialize Weld using ServletContextListener
Feb 10, 2020 5:22:17 PM org.jboss.weld.bootstrap.WeldStartup <clinit>
INFO: WELD-000900: 2.2.14 (Final)
Feb 10, 2020 5:22:17 PM org.jboss.weld.environment.servlet.WeldServletLifecycle initialize
INFO: WELD-ENV-000028: Weld initialization skipped - no bean archive found
Exception in thread "main" java.lang.RuntimeException: java.lang.IllegalStateException: Singleton not set for STATIC_INSTANCE => []
    at io.undertow.servlet.core.DeploymentManagerImpl.deploy(DeploymentManagerImpl.java:224)
    at mainClass.Application.startContainer(Application.java:44)
    at mainClass.Application.main(Application.java:23)
Caused by: java.lang.IllegalStateException: Singleton not set for STATIC_INSTANCE => []
    at org.jboss.weld.bootstrap.api.helpers.RegistrySingletonProvider$RegistrySingleton.get(RegistrySingletonProvider.java:28)
    at org.jboss.weld.Container.instance(Container.java:55)
    at org.jboss.weld.SimpleCDI.<init>(SimpleCDI.java:77)
    at org.jboss.weld.environment.WeldProvider$EnvironmentCDI.<init>(WeldProvider.java:45)
    at org.jboss.weld.environment.WeldProvider.getCDI(WeldProvider.java:61)
    at javax.enterprise.inject.spi.CDI.current(CDI.java:60)
    at org.jboss.weld.servlet.WeldInitialListener.contextInitialized(WeldInitialListener.java:97)
    at org.jboss.weld.servlet.api.helpers.ForwardingServletListener.contextInitialized(ForwardingServletListener.java:34)
    at org.jboss.weld.environment.servlet.Listener.contextInitialized(Listener.java:57)
    at io.undertow.servlet.core.ApplicationListeners.contextInitialized(ApplicationListeners.java:173)
    at io.undertow.servlet.core.DeploymentManagerImpl.deploy(DeploymentManagerImpl.java:195)
    ... 2 more

Can someone help me out in fixing this error ? Is there a much simpler way to integrate Jersey on an undertow Server ?

Note: I have created the application without using any frameworks. I have added JAR files of required libraries.

Answer 1

I also use Undertow fine with Jersey jaxrs-ri fine, but without org.jboss.weld.environment.servlet.Listener . For dependency injections, I just use just jersey built-in support ServiceBinder (subclass of Application) along with org.glassfish.hk2.utilities.binding.AbstractBinder . See https://docs.jboss.org/weld/reference/1.0.0/en-US/html/environments.html